To get 4GB deal add Xbox 360 4GB into your basket then add this (Catalogue number: 209-9524) printer cable which is £1.99, to take the total price to £150.99. Now use £20 off £150 voucher code (TDX-KPRT) at checkout to get the above price. You can add anything to take the total price to £150, i found printer cable to be the cheapest item on their website. I hope this is useful to someone.
dont forget quidco will bag you around another £4 saving with this. 3% cashback atm